Should Olivier Giroud or Alexis Sanchez lead the line for Arsenal?

Has Plan B suddenly turned into Plan A for Arsenal? Olivier Giroud has certainly managed to pose a question few people thought needed answering a few weeks ago: should Alexis Sanchez still be playing up front for the Gunners?

Sanchez seemed to have that position locked down after a string of stellar performances that looked to have consigned a frustrated Giroud to a role as a substitute for the rest of the campaign. The Frenchman was just another option, coming off the bench to be used as a battering ram against tiring opposition or sometimes given a start against defensive teams where a physical presence in the box could be useful.

But Giroud may have turned that thinking on its head by netting three crucial goals in three straight games -- his only league starts of the season -- including THAT scorpion-kick stunner against Crystal Palace. Against West Brom in the previous game, he was fairly ineffective before coming up with a perfect header for a late winner on Boxing Day. But in the 3-3 against Bournemouth on Tuesday, his abilities as a link-up player were crucial to Arsenal's rousing comeback as he set up the first two goals for Alexis Sanchez and Lucas Perez before netting a late equaliser himself.

The last two starts came, in part, thanks to an illness suffered by Mesut Ozil and an injury to Theo Walcott, which forced Arsene Wenger to shuffle his lineup. But given the way Giroud has seized his opportunity, the Arsenal boss now faces quite the conundrum when those two players return.

Does he revert back to a fast-paced attack led by Sanchez that worked so well for much of the season, or does he stick with Giroud up front as long as the Frenchman keeps delivering?

The case for Giroud can be backed up quite easily with numbers: the striker has eight goals in all competitions, despite only making five starts. He has seven goals in his last five league starts, going back to May.

But those numbers can also be used to make a case for Sanchez (who has 15 goals from 25 starts himself). Five of Giroud's eight goals have come after the 70th minute (and three after the 85th), when the opposition defence are tiring and struggling to cope with a tall, strong striker in the box. Giroud has used his size and strength to great effect at times when his team needed him the most, but that ability also highlights why he's so effective as a substitute for this team.

For the opening 70 minutes of games, Arsenal's attack has looked much more dangerous and dynamic with Sanchez leading the line -- not least because of the effect his relentless running and pressing has on teammates Ozil and Walcott.

Giroud inherently slows down Arsenal's game and forces them to break down teams with more intricate passing moves around the box, which so often ends in frustration when the final ball is intercepted. The Frenchman's link-up abilities do play a key part in those types of moves, but defences have had a much harder time dealing with the quicker approach offered by Sanchez.

Teams know exactly what they'll get from Arsenal when Giroud is up front; when Sanchez plays there, expect the unexpected.

The Chile forward remains Arsenal's biggest asset, and their biggest chance of clawing back the deficit to leaders Chelsea. He remains a dangerous player on the wing, but has clearly flourished in the central role where his energy is unleashed to its fullest effect. So while the two can co-exist, playing Sanchez together with Giroud takes away some of his best qualities.

The problem for Giroud is that Arsenal's best team performances this season have all come when he wasn't in the starting XI. His presence in the box certainly offers more of a target but also takes away the possibility for Ozil, Walcott, Alex Iwobi and Alex Oxlade-Chamberlain to exploit the spaces created by Sanchez when he drops deep.

It's no coincidence that Walcott and Ozil have been pouring in goals, often assisted by the Chilean, and while Giroud offers one clear focal point for the attack, Sanchez helps create a three or four-headed monster that is much harder to contain.

Giroud deserves a lot of credit for the way he has responded to losing his regular starting role, and his ability to come up with crucial goals should not be underappreciated. He has certainly done enough to give Wenger food for thought over who leads Arsenal's attack, but for now the answer will likely remain Sanchez.